A379554 Records in A379552.

1, 2, 3, 4, 6, 8, 9, 10, 12, 14, 18, 20, 21, 24, 26, 27, 28, 30, 32, 36, 40, 42, 48, 52, 54, 56, 60, 64, 72, 78, 80, 90, 96, 100, 108, 114, 120, 126, 128, 135, 136, 144, 150, 160, 168, 170, 176, 180, 186, 192, 200, 204, 210, 224, 240, 248, 252, 264, 272, 280, 288

Offset

1,2

Links

Michael De Vlieger, Table of n, a(n) for n = 1..212

Mathematica

r = 0; nn = 10^9;
rad[x_] := Times @@ FactorInteger[x][[All, 1]];
s = Union@ Select[Flatten@ Table[a^2*b^3, {b, Surd[nn, 3]}, {a, Sqrt[nn/b^3]}],
  Length@ Select[FactorInteger[#][[All, -1]], # > 2 &] >= 2 &]; nn = Length[s];
Reap[Do[k = s[[i]]; If[# > r, r = #; Sow[r]] &@
  Count[Transpose@ {#, k/#} &@ #[[2 ;; Ceiling[Length[#]/2]]] &@ Divisors[k],
    _?(And[1 < GCD @@ {##},
    rad[#1] == rad[#2],
    Mod[#1, #2] != 0,
    Mod[#2, #1] != 0] & @@ # &)], {i, nn}] ][[-1, 1]]

Crossrefs

Cf. A376936, A379552, A379553.

Sequence in context: A280196 A143896 A160719 * A263079 A362077 A085451

Adjacent sequences: A379551 A379552 A379553 * A379555 A379556 A379557

Keyword

nonn

Author

Michael De Vlieger, Dec 25 2024

Status

approved